Although the modern sociological study of religion is almost a hundred years old, only recently have behavioral scientists probed religious/spiritual life for its possible health outcomes. The results demonstrate a usually positive correlation between religious involvement and health and mortality. To date, much of the research in this emerging field has used broad measures (e.g. religious attendance), surveyed small, regional populations, and utilized a paucity of minority peoples. In this longitudinal study we plan: 1. To examine particular manifestations of religious experience (e.g. dimensions of prayer and contrasting concepts of God), and their associations with quality of life and cause specific mortality in a Protestant group possessing generally good health outcomes, and increasingly characterized by diversity; 2. To investigate whether these same manifestations of religious experience have different associations with quality of life and cause-specific mortality in two ethnic groups (African- and [Euro- Americans); 3. To examine the possible relationships of these manifestations of religious experience to biochemical and physiological indicators of stress, immune system function, and aging. This prospective study is planned as a complement to LLU's Adventist Health Study-2, currently funded by NCI and enrolling 125,000 participants from across the United States. Whereas AHS-2 focuses on diet and its effect on cancer incidence, our research involving 10,000 of AHS-2 participants will explore how religious beliefs and practices may affect not only mortality but also quality of life. Further, 500 members of the proposed study, ages 50-95+, will live in the Loma Linda vicinity, and participate in the study's clinical arm that will ascertain possible biological and physiological mediators of religious effect. This study should further current understanding of how various manifestations of religion positively and negatively affect physical and mental health.